The present invention relates to an apparatus for the examination of the material of a specimen with local resolution employing an X-ray probe and utilizing the scanning principle, in which apparatus X-ray radiation is generated by a source and is directed onto the specimen by means of an optical system, and the radiation appearing behind the specimen is detected in a detector system.
A device of this type is disclosed in the periodical "Science", Volume 178, pages 608 to 611, November, 1972. In it the synchrotron radiation of an electron synchrotron having an associated optical mirror system and an aperture is utilized for the irradiation while the object is moved physically in a scanning pattern, a loss in intensity of radiation at the optical mirror system and also at the aperture being unavoidable. This is acceptable in practice only if an electron synchrotron or a source with a radiation yield of similar high intensity is available.
A substantial drawback of this device is that its resolving power is limited since, although theoretically the aperture diameter could be limited to 1 micron, this is impossible in practice due to diffraction effects and the fact that, due to roughnesses on the surface of the object, the distance of the aperture from the surface of the object cannot be reduced to an arbitrarily small value.